Santalales
Encyclopedia
Santalales is an order
of flowering plant
s with a cosmopolitan distribution
, but heavily concentrated in tropical and subtropical regions.
Most have seed
s without a testa, which is unusual for flowering plants. Many of the members of the order are parasitic plant
s, mostly hemi-parasites, able to produce sugars through photosynthesis
, but tapping the stems or roots of other plants to obtain water and minerals; some (e.g. Arceuthobium
) are obligate parasites, have low concentrations of chlorophyll
within their shoots (1/5 to 1/10 of that found in their host’s foliage) and derive the majority of their sustenance from the host’s vascular tissues (water, micro- and macro-nutrients, and sucrose). Mistletoe
is the common name for a number of parasitic plants within the order Santalales.
The APG III system
of 2009 (slightly changed from the APG II system
of 2003 and the APG system
of 1998) uses the following circumscription:
The AP-Website indicates that Balanophoraceae
should also be included in this order (post APG II). It also indicates that Olacaceae (sensu APG II) is not a good family and should be split. Furthermore, it indicates doubt about Santalaceae. Studies based on DNA sequences also indicate that the family Schoepfiaceae
should be resurrected (as has been done in the updated APG III-publication) to accommodate Schoepfia (formerly in Olacaceae), Arjona and Quinchamalium (both previously in Santalaceae).
The Cronquist system
(1981) used the following circumscription:
The families Viscaceae and Eremolepidaceae are included in the family Santalaceae by the APG. The genera Dipentodon (Dipentodontaceae) and Medusandra (family Medusandraceae) are regarded as unplaced by APG II (as is the family Balanophoraceae, now likely to be reincluded; see above).
The family Medusandraceae consisted of two genera: Soyauxia and Medusandra. Molecular evidence place them within the family Peridiscaceae of the order Saxifragales. The Chinese monotypic genus Dipentodon is close to Tapiscia and is proposed to constitute the new order Huerteales with Tapisciaceae and the genus Perrottetia formerly placed in the family Celastraceae.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s with a cosmopolitan distribution
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
, but heavily concentrated in tropical and subtropical regions.
Most have seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s without a testa, which is unusual for flowering plants. Many of the members of the order are parasitic plant
Parasitic plant
A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in approximately 19 families of flowering plants are known. Parasitic plants have a modified root, the haustorium, that penetrates the host plant and connects to the xylem, phloem, or...
s, mostly hemi-parasites, able to produce sugars through photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
, but tapping the stems or roots of other plants to obtain water and minerals; some (e.g. Arceuthobium
Arceuthobium
The genus Arceuthobium, commonly called Dwarf Mistletoes, is a genus of 42 species of parasitic plants that parasitize members of Pinaceae and Cupressaceae in North America, Central America, Asia and Africa. Of the 42 species, 39 and 21 are endemic to North America and the United States, respectively...
) are obligate parasites, have low concentrations of chlorophyll
Chlorophyll
Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...
within their shoots (1/5 to 1/10 of that found in their host’s foliage) and derive the majority of their sustenance from the host’s vascular tissues (water, micro- and macro-nutrients, and sucrose). Mistletoe
Mistletoe
Mistletoe is the common name for obligate hemi-parasitic plants in several families in the order Santalales. The plants in question grow attached to and within the branches of a tree or shrub.-Mistletoe in the genus Viscum:...
is the common name for a number of parasitic plants within the order Santalales.
The APG III system
APG III system
The APG III system of flowering plant classification is the third version of a modern, mostly molecular-based, system of plant taxonomy...
of 2009 (slightly changed from the APG II system
APG II system
The APG II system of plant classification is the second, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in April 2003 by the Angiosperm Phylogeny Group. It was a revision of the first APG system, published in 1998, and was superseded in 2009...
of 2003 and the APG system
APG system
The APG system of plant classification is the first, now obsolete, version of a modern, mostly molecular-based, system of plant taxonomy that was published in 1998 by the Angiosperm Phylogeny Group. It was superseded in 2003 by a revision, the APG II system, and then in 2009 by a further...
of 1998) uses the following circumscription:
- order Santalales
- family LoranthaceaeLoranthaceaeLoranthaceae is a family of flowering plants, which has been universally recognized by taxonomists. It consists of about 75 genera and 1,000 species of woody plants, many of them hemi-parasites, all of them except three having the mistletoe habit...
- family MisodendraceaeMisodendraceaeMisodendron is a genus of hemiparasites which grow as mistletoes on various species of Nothofagus. The twelve species are all restricted to South America.Misodendron is placed in its own family, Misodendraceae, in the order Santalales...
- family OlacaceaeOlacaceaeOlacaceae is a family of flowering plants in the order Santalales. They are woody plants, native throughout the tropical regions of the world....
- family OpiliaceaeOpiliaceaeOpiliaceae is the botanical name for a family of flowering plants. It consists of perhaps a dozen genera, totalling several dozen species of tropical woody plants. Several genera contain parasitic species. The biggest genus, in number of species and in stature of the individual plants, is...
- family SantalaceaeSantalaceaeSantalaceae is a widely distributed family of flowering plants which, like other members of Santalales, are partially parasitic on other plants...
- family SchoepfiaceaeSchoepfiaceaeSchoepfiacaceae is the botanical name for a family of flowering plants . Such a family has been recognized by few taxonomists; the plants in question usually being assigned to family Olacaceae and Santalaceae....
The AP-Website indicates that Balanophoraceae
Balanophoraceae
Balanophoraceae is a subtropical to tropical family of obligate parasitic flowering plants, notable for their unusual development and obscure affinities. The family consist of 17 genera and approximately 50 species...
should also be included in this order (post APG II). It also indicates that Olacaceae (sensu APG II) is not a good family and should be split. Furthermore, it indicates doubt about Santalaceae. Studies based on DNA sequences also indicate that the family Schoepfiaceae
Schoepfiaceae
Schoepfiacaceae is the botanical name for a family of flowering plants . Such a family has been recognized by few taxonomists; the plants in question usually being assigned to family Olacaceae and Santalaceae....
should be resurrected (as has been done in the updated APG III-publication) to accommodate Schoepfia (formerly in Olacaceae), Arjona and Quinchamalium (both previously in Santalaceae).
The Cronquist system
Cronquist system
The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in his texts An Integrated System of Classification of Flowering Plants and The Evolution and Classification of Flowering Plants .Cronquist's system places flowering plants into two...
(1981) used the following circumscription:
- order Santalales
- family MedusandraceaeMedusandraceaeMedusandra is a genus of flowering plants in the family Peridiscaceae. It has two species, Medusandra richardsiana and Medusandra mpomiana. M. richardsiana is the most common and well known. Both species are native to Cameroon and adjacent countries. Medusandra was named by John Brenan in 1952...
- family DipentodontaceaeDipentodontaceaeDipentodon is a genus of flowering plants in the family Dipentodontaceae. Its only species, Dipentodon sinicus, is a small, deciduous tree native to southern China, Burma, and northern India. It has been little studied and until recently its affinities remained obscure.- Description :Dipentodon...
- family OlacaceaeOlacaceaeOlacaceae is a family of flowering plants in the order Santalales. They are woody plants, native throughout the tropical regions of the world....
- family OpiliaceaeOpiliaceaeOpiliaceae is the botanical name for a family of flowering plants. It consists of perhaps a dozen genera, totalling several dozen species of tropical woody plants. Several genera contain parasitic species. The biggest genus, in number of species and in stature of the individual plants, is...
- family SantalaceaeSantalaceaeSantalaceae is a widely distributed family of flowering plants which, like other members of Santalales, are partially parasitic on other plants...
- family MisodendraceaeMisodendraceaeMisodendron is a genus of hemiparasites which grow as mistletoes on various species of Nothofagus. The twelve species are all restricted to South America.Misodendron is placed in its own family, Misodendraceae, in the order Santalales...
- family LoranthaceaeLoranthaceaeLoranthaceae is a family of flowering plants, which has been universally recognized by taxonomists. It consists of about 75 genera and 1,000 species of woody plants, many of them hemi-parasites, all of them except three having the mistletoe habit...
- family ViscaceaeViscaceaeViscaceae is a family of flowering plants. In past decades, several systems of plant taxonomy recognized this family, notably the 1981 Cronquist system...
- family Eremolepidaceae
- family BalanophoraceaeBalanophoraceaeBalanophoraceae is a subtropical to tropical family of obligate parasitic flowering plants, notable for their unusual development and obscure affinities. The family consist of 17 genera and approximately 50 species...
The families Viscaceae and Eremolepidaceae are included in the family Santalaceae by the APG. The genera Dipentodon (Dipentodontaceae) and Medusandra (family Medusandraceae) are regarded as unplaced by APG II (as is the family Balanophoraceae, now likely to be reincluded; see above).
The family Medusandraceae consisted of two genera: Soyauxia and Medusandra. Molecular evidence place them within the family Peridiscaceae of the order Saxifragales. The Chinese monotypic genus Dipentodon is close to Tapiscia and is proposed to constitute the new order Huerteales with Tapisciaceae and the genus Perrottetia formerly placed in the family Celastraceae.